We analyzed an expression system of SPINK1 of normal gastric mucosa epithelium and analyzed it in gastric cancer at the same time. SPINK1 expressed to a gastric mucosa cell and worked in protection of gastric mucosa and vulnerary acceleration of ulcer locus. It was particularly strongly confirmed expression in crypt in a stomach and expressed to the cell which had a property of stem cell. We particularly strongly expressed in well differentiated type in gastric cancer, and did not recognize most expression about undifferentiated carcinoma.